Narrowing of the emission spectrum of a wide-band laser and locking to one- and two-photon absorption lines of a medium with a light-induced anisotropy

An experimental investigation was made of the spectral and energy characteristics of the radiation emitted by a dye laser with a ring resonator containing an absorbing medium (potassium vapor) in which an anisotropy was induced by a strong external optical wave. Narrowing of the dye output radiation to about 10 ^– 2 nm and locking of the emission spectrum to one- and two-photon absorption lines of the potassium vapor were observed. An investigation was made of the locking efficiency for different polarizations of the strong wave.